new PC randomly crashing

[yiffyouth]

Hey. 
a few weeks ago i built my first PC. 

I had a friend come over to help me with the build.
we put it all together and when i flipped the switch on the powwer suply all the RGB lights from the moba and ram turned on. but when i tried to turn it on nothing happened. i tought i plugged the fron panel cables wrong but then i tried to turn it on by shorting the two pins on the moba and it stil didn't work. then we realized that the gpu was powered with de cpu cable instead of pcie. I swapped the cables and everything worked. After a day it froze (it was acting like it had no ram. i could move the mouse and open up the windows menu but i couldn't do anything) it's freezing in random moments. once it froze while i wass saving a game level but it also freezes while browsing the web. it happens once a day. 
I noticed a burn on the gpu but i was able to wipe it off with some isopropyl alcohol.
Do you think it's the gpu?
i have 2 another guesses. 
This ram is compatible with my moba but the black version and not the one that i have
while i was cleaning the old m.2 drive (i took of the old heatsink that was on it) i might have damaged something.
Specs:
AMD Ryzen 7 3800X

GTX 1070 ASUS Dual OC 8GB
Corsair 16GB (2x8GB) 3600MHz CL18 Vengeance RGB PRO SL Wh

Gigabyte B550 AORUS ELITE AX V2

be quiet! Pure Power 11 FM 750W 80 Plus Gold

 

[Aashishkebab]

2 hours ago, yiffyouth said:

I noticed a burn on the gpu

Can you specify what you mean by this? Like a black mark?

 

All RAM with your DIMM configuration is compatible technically but what matters is your speed. What are your RAM frequency and timings in BIOS? You are experiencing symptoms of bad memory.

[yiffyouth]

Just now, Aashishkebab said:

Can you specify what you mean by this? Like a black mark?

 

All RAM with your DIMM configuration is compatible technically but what matters is your speed. What are your RAM frequency and timings in BIOS? You are experiencing symptoms of bad memory.

I set the ram to the XMP profile (3600Mhz)
ill send a photo of the burn in a minute

[yiffyouth]

6 minutes ago, Aashishkebab said:

Can you specify what you mean by this? Like a black mark?

 

All RAM with your DIMM configuration is compatible technically but what matters is your speed. What are your RAM frequency and timings in BIOS? You are experiencing symptoms of bad memory.

Before and after cleaning